Eating disorders are defined as eating habits that are harmful to an individual's health and involve issues with food and weight. The three most common types are anorexia nervosa, bulimia nervosa, and binge eating disorder. Anorexia is characterized by self-starvation and excessive weight loss. Bulimia involves cycles of binge eating followed by purging. Binge eating disorder involves periods of uncontrolled eating beyond fullness. Eating disorders can have serious medical and psychological complications and require professional help.